Improvements in DH_OPTIONS handling and DH_AUTO_OPTIONS envvar support.

* DH_AUTO_OPTIONS is like existing DH_OPTIONS, just only for dh_auto
  stuff. This also avoids "explosion" of separate DH_AUTO_* environment
  variables (i.e. exports in debian/rules) and encourages usage of dh_auto
  command line option names. DH_AUTO_OPTIONS is passed via "extra_args" to
  Dh_Lib::init() (API addition).
* When splitting options from DH_OPTIONS and its flavours, allow arguments
  to include whitespaces if they are escaped with backslash (\) (see
  split_options_string()). Document this in debhelper.pod.
* Short option for --buildsystem is -c (aka class).
* Provide API to cancel option specs from default debhelper options.
  It will be used in the feature.

4 files changed, 53 insertions, 26 deletions

diff --git a/Debian/Debhelper/Dh_Buildsystems.pm b/Debian/Debhelper/Dh_Buildsystems.pm
index 80b66887..be29ac5c 100644
--- a/Debian/Debhelper/Dh_Buildsystems.pm
+++ b/Debian/Debhelper/Dh_Buildsystems.pm
@@ -65,27 +65,23 @@ sub load_buildsystem {
 sub buildsystems_init {
 	my %args=@_;
 
-	# TODO: Not documented in the manual pages yet.
-	# Initialize options from environment variables
-	if (exists $ENV{DH_AUTO_BUILDDIRECTORY}) {
-		$opt_builddir = $ENV{DH_AUTO_BUILDDIRECTORY};
-	}
-	if (exists $ENV{DH_AUTO_BUILDSYSTEM}) {
-		$opt_buildsys = $ENV{DH_AUTO_BUILDSYSTEM};
-	}
-
 	# Available command line options
 	my %options = (
 	    "b:s" => \$opt_builddir,
 	    "builddirectory:s" => \$opt_builddir,
 
-	    "m=s" => \$opt_buildsys,
+	    "c=s" => \$opt_buildsys,
 	    "buildsystem=s" => \$opt_buildsys,
 
 	    "l" => \$opt_list,
 	    "--list" => \$opt_list,
 	);
-	map { $args{options}{$_} = $options{$_} } keys(%options);
+	$args{options}{$_} = $options{$_} foreach keys(%options);
+
+	# Pass options from the DH_AUTO_OPTIONS environment variable
+	if (defined $ENV{DH_AUTO_OPTIONS}) {
+		$args{extra_args} = $ENV{DH_AUTO_OPTIONS};
+	}
 	Debian::Debhelper::Dh_Lib::init(%args);
 }
 
diff --git a/Debian/Debhelper/Dh_Getopt.pm b/Debian/Debhelper/Dh_Getopt.pm
index 5585a54c..bddc06b8 100644
--- a/Debian/Debhelper/Dh_Getopt.pm
+++ b/Debian/Debhelper/Dh_Getopt.pm
@@ -71,9 +71,9 @@ sub NonOption {
 
 sub getoptions {
 	my $array=shift;
-	my %options=%{shift()} if ref $_[0];
+	my $extraoptions=shift;
 
-	Getopt::Long::GetOptionsFromArray($array,
+	my %options=(
 		"v" => \$dh{VERBOSE},
 		"verbose" => \$dh{VERBOSE},
 
@@ -137,24 +137,42 @@ sub getoptions {
 		
 		"ignore=s" => \&AddIgnore,
 
-		%options,
-
 		"<>" => \&NonOption,
-	)
+	);
+	
+	# Merge extra options and cancel default ones as needed (undef)
+	if (defined $extraoptions) {
+		for my $opt (keys %$extraoptions) {
+			if (defined $extraoptions->{$opt}) {
+				$options{$opt}=$extraoptions->{$opt};
+			}
+			else {
+				delete $options{$opt};
+			}
+		}
+	}
+
+	Getopt::Long::GetOptionsFromArray($array, %options);
+}
+
+sub split_options_string {
+	my $str=shift;
+
+	$str=~s/^\s+//;
+	return map { $_=~s/\\(\s)/$1/g; $_=~s/\s+$//g; $_ } split(/(?<!\\)\s+/,$str);
 }
 
 # Parse options and set %dh values.
 sub parseopts {
 	my $options=shift;
+	my $extra_args=shift;
 	
 	my @ARGV_extra;
 
 	# DH_INTERNAL_OPTIONS is used to pass additional options from
 	# dh through an override target to a command.
 	if (defined $ENV{DH_INTERNAL_OPTIONS}) {
-		$ENV{DH_INTERNAL_OPTIONS}=~s/^\s+//;
-		$ENV{DH_INTERNAL_OPTIONS}=~s/\s+$//;
-		@ARGV_extra=split(/\s+/,$ENV{DH_INTERNAL_OPTIONS});
+		@ARGV_extra=split_options_string($ENV{DH_INTERNAL_OPTIONS});
 		my $ret=getoptions(\@ARGV_extra, $options);
 		if (!$ret) {
 			warning("warning: unknown options will be a fatal error in a future debhelper release");
@@ -183,15 +201,22 @@ sub parseopts {
 	# to be parsed like @ARGV, but with unknown options
 	# skipped.
 	if (defined $ENV{DH_OPTIONS}) {
-		$ENV{DH_OPTIONS}=~s/^\s+//;
-		$ENV{DH_OPTIONS}=~s/\s+$//;
-		@ARGV_extra=split(/\s+/,$ENV{DH_OPTIONS});
+		@ARGV_extra=split_options_string($ENV{DH_OPTIONS});
 		my $ret=getoptions(\@ARGV_extra, $options);
 		if (!$ret) {
 			warning("warning: ignored unknown options in DH_OPTIONS");
 		}
 	}
 
+	if (defined $extra_args) {
+		my @extra_opts=split_options_string($extra_args);
+		my $ret=getoptions(\@extra_opts, $options);
+		if (!$ret) {
+			warning("warning: ignored unknown options");
+		}
+		push @ARGV_extra, @extra_opts;
+	}
+
 	my $ret=getoptions(\@ARGV, $options);
 	if (!$ret) {
 		warning("warning: unknown options will be a fatal error in a future debhelper release");
diff --git a/Debian/Debhelper/Dh_Lib.pm b/Debian/Debhelper/Dh_Lib.pm
index 28a90f7b..b3162d07 100644
--- a/Debian/Debhelper/Dh_Lib.pm
+++ b/Debian/Debhelper/Dh_Lib.pm
@@ -29,10 +29,10 @@ sub init {
 	# Getopt::Long, which I'd prefer to avoid loading at all if possible.
 	if ((defined $ENV{DH_OPTIONS} && length $ENV{DH_OPTIONS}) ||
  	    (defined $ENV{DH_INTERNAL_OPTIONS} && length $ENV{DH_INTERNAL_OPTIONS}) ||
-	    grep /^-/, @ARGV) {
+ 	    (defined $params{extra_args}) || grep /^-/, @ARGV) {
 		eval "use Debian::Debhelper::Dh_Getopt";
 		error($@) if $@;
-		Debian::Debhelper::Dh_Getopt::parseopts($params{options});
+		Debian::Debhelper::Dh_Getopt::parseopts($params{options}, $params{extra_args});
 	}
 
 	# Another way to set excludes.
diff --git a/debhelper.pod b/debhelper.pod
index 388453c3..8c232d28 100644
--- a/debhelper.pod
+++ b/debhelper.pod
@@ -491,8 +491,14 @@ Anything in this variable will be prepended to the command line arguments
 of all debhelper commands. Command-specific options will be ignored by 
 commands that do not support them. 
 
-This is useful in some situations, for example, if you need to pass -p to
-all debhelper commands that will be run. One good way to set DH_OPTIONS is
+Arguments are separated by whitespaces unless a whitespace is escaped
+with a backslash character (\). Then the whitespace is treated literally.
+Likewise, the backslash character is treated literally unless it is followed
+by a single whitespace. If a backslash is followed by two or more spaces,
+it will be considered as the last symbol of the argument.
+
+DH_OPTIONS is useful in some situations, for example, if you need to pass -p
+to all debhelper commands that will be run. One good way to set DH_OPTIONS is
 by using "Target-specific Variable Values" in your debian/rules file. See
 the make documentation for details on doing this.